Abstract: A method of making a mineralized fiber having a fiber core and a calcium carbonate shell can include admixing fibers with green liquor and adding CaO to generate a causticization reaction that results in a calcium carbonate shell coating forming around the fibers.

Abstract: The current invention relates to methods of the recovery and re-use of minerals obtained from the combustion of the residues of a process to recycle paper.

Abstract: The current invention relates to methods of the recovery and re-use of minerals obtained from the combustion of the residues of a process to recycle paper.

Abstract: A process produces PCC from lime mud generated in the kraft pulping process. The process includes providing an aqueous suspension of lime mud, neutralizing the lime mud suspension, separating grit particles from the lime mud suspension, dewatering the lime mud suspension to produce dewatered lime mud solids, washing the dewatered lime mud solids to produce washed lime mud solids, and milling the washed lime mud solids to produce a PCC suitable for use as a filler and/or coating pigment for paper and paperboard.

Abstract: A method of recycling mineral pigments contained in the waste produced from the deinking of wastepaper. The deink residue is heated in an oxygen-containing atmosphere to a temperature sufficient to completely oxidize all the organic hydrocarbons present. Heat, water, and carbon dioxide also are generated and may be captured and reused in the process. Combustion causes a chemical reaction to occur, so that the original pigments contained in the deink residue are converted to new, stable mineral forms. The ash from the combustion is primarily a mixture of gehlenite (Ca.sub.2 Al.sub.2,SiO.sub.7), anorthite (CaAl.sub.2 Si.sub.2 O.sub.8) and perovskite (CaTiO.sub.3). The ash containing the mixed mineral phases is added to a reactor in which carbon dioxide gas is bubbled through an aqueous slurry of calcium hydroxide so that precipitated calcium carbonate (PCC) is produced.